My brother had a really bad experience with Marshall Mayor. The lovely painting fell off. They sounded un-natural. And the right driver broke after 4 month of normal use with an Ipod. I can't talk for the Monitor, but if those are made by the same company who made Marshall Mayors (And Urbanears) I feel I must warn you about them.

I can't talk for the Fidelio X1 neither. I have a pair of L1 which are far of being my favourites, every time I use them I feel I'm loosing detail and naturalness in music which I can easily get just by taking another headphones.

L1s are made of solid materials, they look nice. This headphones also have great bass extension but not great impact, and bring voices, especially female voices, to the front. To me they often sound congested in the upper mids.

I have a pair of X1's and I enjoy them quite a bit. I would say that Me x3's impression of the L1's somewhat extends to the X1. They are fairly V-shaped in frequency response, and have good low end. In your price range, you won't be seeing much in the way of impeccable separation and punch, but I will say the X1's are extremely comfortable, have good bass extension, and are occasionally bright with treble. They're also very easy to drive. They can be used directly with the source, really. Good luck on the hunt, though!

My brother had a really bad experience with Marshall Mayor. The lovely painting fell off. They sounded un-natural. And the right driver broke after 4 month of normal use with an Ipod. I can't talk for the Monitor, but if those are made by the same company who made Marshall Mayors (And Urbanears) I feel I must warn you about them.

I can't talk for the Fidelio X1 neither. I have a pair of L1 which are far of being my favourites, every time I use them I feel I'm loosing detail and naturalness in music which I can easily get just by taking another headphones.

L1s are made of solid materials, they look nice. This headphones also have great bass extension but not great impact, and bring voices, especially female voices, to the front. To me they often sound congested in the upper mids.

I read a thread on Head-Fi and people were comparing the Marshall Monitor's soundstage to the one of the Audio Technica ATH-m50, just better, with better bass too. People also say that the build quality is very good, not v-moda good, but not bad at all. I've tried them at a local bestbuy and they do not sound anyway close to the Majors, which surprised me. Now I'm no audiophile but I think the Marshall Monitors are pretty good.

X1 has issues, the cable has high resistance and the ear pads cannot be replaced. You can get a DT990 pro + a decent amp(O2/Magni) and be happy. DT990 has great soundstage and imaging and an earth shattering bass when called for. treble is detailed and nice but some people find it to be a bit fatiguing.

I have begun to realize that my price range really is the limiting factor. If I raised the amount to five-hundred however, would my options change.
I have heard good things about the K702, is the anniversary edition actually better than the normal though?

At under $500, you're still looking at K70x / Q701. The only sound difference between the annie and the regular K702 is the pads which can be bought separately.